var bttn = document.querySelector('.btn')

bttn.addEventListener('mouseover',(e)=>{
    const x = (e.pageX - e.target.offsetLeft)
    const y = (e.pageY - e.target.offsetTop)

    bttn.style.setProperty("--x", x + 'px')
    bttn.style.setProperty("--y", y + 'px')
})